Telephone transmission system



R. S. WILBUR.

TELEPHONE TRANSMISSION SYSTEM.

APRLICATION FILED DEC. 10, 1917. 1,361,510.

Patented Dec. 7; 1920.

Affjl.

071/6/7/02 5: Ra /5. W/Vfiar.

.s'ra'rps R a w nson, or LYNDHURST, NEW JERSEY, ASSIGNOR T0 wns'rnan ELECTRIC PATENT OFFICE;

COMPANY, mooaronarnn, or new YORK, n. Y., A CORPORATION on NEW YORK,

TELEPHONE TRAN$MISS ION SYSTEM.

Application filed December 10, 1917.

To all whom it may concern:

Be it known that I, RAY SETH 'VVILBUR, a

citizen of the United States, residing at Lyndhurst, in the county of Bergen, State of New Jersey, have invented certain new This invention relates to telephone repeater circuits, and more particularly to twoway, two-repeater circuits with which is associated means for amplifying ringing current or other signaling current, as well 'as telephonic currents.

An object of this invention is the provision of a system of this character in which the length of line over which signaling devices may be satisfactorily operated is increased.

In telephone repeater circuits and especially those of the two-way, two-repeater type, the telephone line is divided into sections, two sections being joined at a repeater station by means of two repeaters. The input side of each repeater is connected to a line-section through a potentiometer and a frequency filter for obtaining the best possible gain in amplification of telephonic currents and the output side of each repeater is connected in circuit with the primary winding oi an output repeating coil whose secondary windings are connected in circuit with the opposite linc section. The repeaters employed, when of the well-known vacuum tube t 'pe,may'also he'employed for amplifying ringing current as well as telephonic 3 rrents.

ln accordaiu-e with the present invention,

a telephone repeater circuit of this type is provided with means located at the repeater station and responsive to ringing current incoming over one line section; first, to connect the input side of the repeater direct to the incoming line section independently of the potentiometer and filter; second. to short-circuit the primary winding of the output repez-iting coil whose secondary is connected in the incoming line section and third, to disconnect the usual artificial line and output repeating .coil from the outgoing line section and to connect the output side of the anuiliiying repeater with the. outgoing line section through a separate repeating coil.

.This invention will. be best understood Specification of Letters iatent.

Patented Dec. 7, 1920.

Serial No. 206,420.

from the following description when considered in connection with the accompanylng drawing, in which Figure 1 shows the two-way repeater telephone circuit containlng the preferred embodiment of this invention; Fig. 2 shows a modification of Fig. 1 in which the ringing responsive means is connected to the input side of the repeater.

Referring to Fig. 1 of the drawing, there are shown two sections 11 and 12 of a telephone line, which are joined. through re peat er apparatus at a two-way, two-repeater station. prises two vacuum tube repeaters 13- and 14 and their associated apparatus. Repeater 13 is adapted to receive signalsltransmitted to the station over line section 11 and to transmit amplified signals from the station over the line section 12. Ina similar manner repeater 14 amplifies signals received over line section 12 and transmits such amplified signals over line section 11. The input circuit for repeater 13 comprises the windings of which are connected in the line section 12. This repeating coil 20 serves to transmit into line section 12 amplified talking currents. A relay 21 having two electromagnets in series with a condenser 22 connected in bridge of another condenser 23 is in series with the primary winding of the output repeating coil 20. Condenser 23 is of such capacity that when in circuit with the primary Winding of the repeating coil 20, the circuit is resonant to currents of talking frequenciesu Condenser 22 is of such capacity that when in circuit with the windings of relay 21, the circuit is resonant to currents of ringing or signaling frequencies. It will be understood, therefme. that relay 21. is not affected by currents of talking fre qucncies. An artificial balancing line 24 is connected in circuit with the secondary l The repeater arrangement compeating windings of the output repeating coil 20. The connection and use of artificial balancing lines is well-knownin the art, a similar arrangement of such as used by applicant being shown in Patent N 0. 1,029,724 of June 18, 1912, to Shuhert.

The input circuit of the repeater comprises the upper and middle normally closed contacts of relay 43, impedance coils 25, 25 and condensers 26, 26, which cooperate and serve as a filter to filter out frequencies above the usual talking range, a. potentiometer 27, normally closed contacts of relay 28 and the primary Winding of an input recoil 29, the secondary of which is connected in circuit with battery and the filament and the grid of the repeater 14. The filament and the plate of the repeater 14 are in circuit with the primary winding of the output repeating coil 30, the secondary windings of which are connected in the line section 11. This repeating coil 30 serves to transmit. amplified talking currents from the repeater 14 into the line section 11. Re

lay31 and condensers. 32 and 33 are associated with the output repeating coil 30 in precisely the same manner as relay 21 and condensers 22- and 23 are associated with the output repeating coil 20, and function in the same manner. An artificial balancing line 34 is also associated with the out put repeating coil 30. Relay 43 is controlled by relay 18 and when operated disconnects .line section 12- from the output repeating coil 20 and the artificial line 24 and connects it (line section 12) with another repeating coil 45, which serves to transmit into line section'12 amplified ringing current received from the repeater 13. Relay 42 is controlled by relay 28 and when operated disconnects line section 11 from the output repeating coil 30 and the artificial line 34 and connects it (line section 11) with a repeating coil 44, which serves to transmit into line section 11 currents amplifled by the repeater 14.

It Will be assumed that ringing current or other currents having characteristics differing from telephonic currents is transmitted to the repeater station over line section 11. This ringing current passes from the line section 11, through the upper and middle normal contacts of relay 42, and the secondary windings of the output repeating coil 30, impedance coils 15, 15, potentiometer 17, normal contacts of relay 18 and the primary winding of' the input repeating coil 19. Current is thereupon induced into the secondary circuit which includes the filament and the grid of the repeater 13 and is thereby amplified and'repeated into the circuit including the windings of relay 21. Relay 21 thereupon operates to open its contact, releasing relay 40. Relay 18 is thereby operated over a circuit from battery through ratus functions the winding of relay 18 and the contact of relay 40 to ground. Relay 18, in operating, performs the following functions: First, the connection of. the primary winding of the repeating coil 19 to the line section 11 inde pendently of the frequency filter and the po-, tentiometer; second, disconnects the frequencyfilter and the potentiometer from the primary winding of the input repeating coil 19; third, short-circuits the primary winding of the output repeating coil 30, and fourth, causes the operation which includes the u tact of relay 18. elay 43, in operating disconnects the repeating coil 20 and the artificial line 24 from the line section 12 and connects this line section 12 in circuit with the secondary winding of the repeating coil 45, and also disconnects the output side of the repeater 13 from the primary winding of the repeating coil 20 and connects it with the primary winding of the repeating coil 45. When ringing current incoming from the line section 11 first traverses the secondary windings ofthe output repeating coil 30, there may be suflicient current in- .duced in the primary winding thereof to operate relay 31, thereby momentarily releasing relay 41 and operating'relay 28.

'owever, if thiscondition exists, it is but for a verys'hort period, for, as soon as the of relay 43 over a circuit permost alternate conamplified ringing current operates relay 21,

relay 40 releases to permit the operation of relay 18, which immediately short-circuits primary winding of the outpiut repeating coil 30 as already described. elay 31 will, therefore, immediately release, permitting relay 41 to open the circu-itof'relay 28. In other words, while both relays 21 and 31 may be operated by ringing current incoming to the repeater station over either line section only the relay receiving amplified ringing current will remain operated. Amplified ringing current traversing the winding of relay 21 also traverses the'primary winding of repeating coil 45, which is now, connected in circuit, since relay 43 has operated. Amplified ringing current will, therefore, be induced into the secondary winding of the repeating coil 45, which is in circuit with the line section 12. This ing current transmitted from line section 11, amplified at the repeater station and then induced in the line section 12 through the. Windingsof the repeating coil 45, may be employed to operate signaling devices .of any suitable-character. I

' rom this brief description, it is thought it will be clearly understood that'the appa to receive ringing current from line section 12 and to amplify and then. to transmit such amplified ringing current into line section 11.

I By employing the relays 42 and 43 which, when operated, disconnect the respective ringciated repeaters.

artificial lines from the line sections, permits of an increase in the length oi: line 'over which signaling devices may be satisfactorily operated. Furthermore, the use of separate repeating coils 14 and 45 for transmitting the amplified ringing currents into the respective line sections also permits an increase inthe length of the line over which signals may be satisfactorily operated, for the reason that such repeating coils may be especially designed to efiiciently repeat ringing currents which are usually of low frequency. The short-circuiting of the primary winding of the output repeating coil connected in the incoming line section, prevents interference in the control relays at the repeater station. Fig. 2 shows how relays 21 and 31 and their associated condensers 22 and 32, respectively, may be connected to the input side of their asso- For example, instead of connecting the Wires leading from condenser 22 and the right-hand winding of relay 21 to the terminals of condenser 23, as shown in Fi n 1, these wires may be connected to the middle point of the secondary winding 1 of repeating coil. 30, as shown in Fig. 2.

In a like manner the wires leading from condenser 32 and the left-hand winding of relay 31 to the terminals of condenser 33, as shown in Fig. 1, may be connected to the middle point of the-secondary winding of repeating coil 20, as shown in Fig. 2. Otherwise, the connections remain as shown in Fig. 1.

Ringing current passing from the line section through the upper and inner lower normal contacts of relay 12 into the sec ondary winding of output repeating coil 30 will divide, a portion passing through the primary winding of repeating coil 19 as heretofore described, and a )ortion through the winding of relay 21. elay 21 thereupon operates to open its contact, releasing relay 10, thereby operating relay 18. Relay 18 in operating performs the same functions as heretofore described; As soon as relay 21 operates and relay 4:0 releases its armature to permit the operation of relay 18, the primary winding of the output repeating coil 30 is short-circuited, as before described. Ringing current traversing the primary winding of repeating coil 19 causes ringing current to be induced in the secondary windingof repeating coil 19 which includes the filament and grid of repeater 13. The ringing current is thereby amplitied and repeated into the circuit including the primary winding of repeating coil 45 which is now included in circuit, since relay 13 has operated. Amplified ringing current will tieretore be induced into the secondary winding of repeating coil 45 which is in circuit with the line section 12. In this brief description it is thought that it will be clearly understood that relays 21 and 31 perform the same functions when connected as shown in Fig. 2 as when connected as shown in Fi 1 of the drawing.

What is claimed is:

1. A telephone transmission system comprising two line sections, a repeater for am plifying talking and ringing currents, a potentiometer normallyconnecting the input side of the repeater with one line section, means operatively connected with the one line section and responsive to ringing current to connect the repeater thereto independently of the potentiometer, and means for transmitting amplified ringing current from the repeater into the other line section.

2. A telephone transmission system comprising two line sections, a repeater for ampli't'ying talking and ringing currents, a potentiometer normally connecting the input side of the repeater with one line, a relay ope 'atively connected with the one line section and responsive to ringing current, and a second relay energized upon the response of the first relay to connect the repeater to the one line section independently of the potentiometer, and means for transmitting amplified ringing current from the repeater into the other line section.

3. A telephone transmission system comprising two linesections, a repeater 'lor amplifying talking and ringing currents and having its input side connected with one line section, a repeating coil connecting the output side oi the repeater with the other linesection for. transmitting thereto amplified talking currents, another repeating coil for transmitting amplified ringing current into said other. line section, and means responsive to ringing current incoming ,over 'the one line section for substituting the second repeating coil for the first.

4: A telephone transmission system com prising two line sections, a repeater for amplifying talking and ringing currents and having its input side connected with one line section, a repeating coil connecting the output side of the repeater with the other line section for transmitting thereto amplified talking currents, another repeating coil for transmitting amplified ringing current into said other line section, a relay responsive to ringing current incoming over the one line section, and a. second relay energizedupon the response of the first relay for substituting the second repeating coil for the first.

5. A telephone transmission system comprising two line sections, 'a repeater for amplifying talking and ringing currents, at

potentiometer normally connecting. the input side of the repeater with one line section, a repeating coil connecting the output side of the repeater with the other line section for transmitting thereto amplified talking currents, a relay "with .one line section, a repeatingcoil for each line section, each connecting with one line section the output side of the repeater whose input side is associated with the other line section, and means responsive to ringing current incoming over one line section for short-circuiting the primary winding of the repeating coil connected with that section.

7. A telephone transmission system comprisin two line sections, two repeaters for amplifying talking and ringing currents, each repeater having its input side associated with one line section, a repeating coil for each line section', each connecting with one line section the output side of the repeater whose input side is associatedwith the other line section, a relay responsive to ringing current incoming over one line section, and a second relay-energized upon the response of the first relay for short-circuiting. the primary winding of the repeating coil connected with that section.

8. A telephone transmission system comprising two .line sections, a potentiometer for each line section, two repeaters for amplifying talking and ringing currents, each repeater having its input side associated w h one line section, a repeating-coil foreach line section, each connecting with one line section the output side of the repeater whose input side is associated with the other line section, and means responsive to ringing current over oneline section to connect its associated repeater thereto independently of the associated potentiometer and to short-circuit the primary winding of the repeating coil connected with that line section.

9. A telephone transmission system comprising two line sections, a potentiometer for each l1nesect1on,,.two repeaters for amplifying talking and ringing currents,

. each repeater having its input side alsociated with one line section, a repeating coil for each line section, each connectlng -Wlth one line section the output side of the re-,

peaterwhose input side is associated with 1 they other line section, a relay responsive to ringing current,over one line section, and a i second relay energized upon the response of (the first relay to' connect the associated repeater to said one line section inde endently of the associated potentiometer, an to short circuit the primary winding of the repeatmg coil connected with said one line section.

l0. A telephone transmission system comprising two line sections, a repeater for amplifying talking and ringing currents and having its input side connected with one line section, a circuit normally connecting the output side of the repeater with the other line section for transmitting thereto amplified currents of one character, an auxiliary circuit over which amplified currents of the other character may be transmitted into said other line section, and means responsive to currents of said other character incoming over the one line section forsubstituting the auxiliary for the normal circuit.

11. A telephone transmission system comprising two line sections, a repeater for amplifying talking and'ringing currents and having its input side connected with one linevso section, a circuit normally, connecting the 7 output side of the repeater with the other line section for transmitting thereto amplified talking currents, an auxiliary circuit over WlllCh amplified ringing currents maybe transmitted into the said other line see tion, and a relay responsive to ringing currents incoming from the one line section for controlling the substitution of the auxiliary for the normal circuit.

12. A. telephone transmission system comprising two line sections, two repeaters for amplifying talking and signaling currents,

' each repeater having its input side associated with one line section, a repeating coil for each line section each connecting with one line section the output side of the repeater whose input side is associated with the other line section, and means responsive to signalmg current in'comlng over one line sectlon,

for operatively disconnecting the primar winding of the repeating coll connected wit that section.

13. A telephone transmission system com-.

prising two line sections, a repeater for amplifying'talking and ringing currents, current regulating means normally connecting the input side of the repeater with one line section, means operatively connected with the one line section and responsive to ringing current to connect the repeater thereto Independently of the current regulating means,

and means for transmitting amplified ringing current from line section.

14. A telephone transmission system comprising two line sections, a repeater for amlifying talking and signaling currents havmg its output side connected with one line section, current regulating means normally connecting the input side of the repeater with the repeater into the other the other line section, and means operatively connected with said other line section and responsive to signaling current to connect the input side of the repeater thereto independently of the current regulating means.

15. A telephone transmission system comprising two line sections, a repeater for amplifying alking and signaling currents having its output side connected with one line section, means controlling the amplification of the repeater normally connecting the input side thereof with the other line section, and means associated with said other line section and responsive to signaling current transmitted thereover to connect the input side of the repeater with said other line section independently of the amplification controlling -means.

16. A telephone transmission system comprising two line sections, an artificial balancing line associated with each line section,

two repeaters for amplifying talking and signaling currents, each repeater having its input side connected with one line section and its output side connected With the other line section and its associated artificial line so that substantially half ofthe output energy is transmitted to the artificial line, and means responsive to signaling current transmitted over one line section for disconnect ing the artificial line from the other line section.

17. A. telephone transmission system comprising two line sections, an artificial balancing line associated with each line section, two repeaters for amplifying talking and signaling currents, eachrepeater having its input side connected with one line section and its output side connected with the other line section and its associated balancing line so that substantially half of the output energy is transmitted to the artificial line, and a relay responsive to signaling current transmitted over one line section controlling the disconnection oi the output side of ihe repeater associated with said section from the other line section and artificial line, and the connection thereof with said other line section independently of the artitical line two line sections, a repeater for amplifying talking and signaling currents having its 18. In a transmission system comprising input circuit connected with one section, and its output circuit connected with the other section, and means responsive to signaling current for increasing the eiiiciency of the system to signaling current 19. In a transmission system comprising two line sections, a repeater for amplifying talking and signaling currents having its input circuit connected with-one section, and its output circuit connected with the other section, and means responsive to signaling current to change the circuit connections to modify the transmission of the signaling current.

20. In a transmission system, an incoming line adapted to receive a plurality of sets of currents of different frequencies, an outgoing line adapted to transmit said sets, a repeater between said lines, and means responsive to the receipt of one of said sets to modify the transmission of said set. 21. In a transmission system, an incoming line adapted to receive a plurality of sets of currents of different frequencies, an outgoing line adapted to transmit saidfrequencies, a repeater between said lines, and means responsive to the receipt of one of said sets to change the circuit connections to modify the transmission of saidset.

22.111 a transmission system comprising two line sections, a repeater for repeating a plurality of sets of currents of different frequencies having its input circuit connected with one section and its output circuit connected with the ,other section, and means responsive to the impression of one of said sets to modit'y'the transmission of said set.

23. In a transmission system comprising two line sections, a repeater for repeating a plurality of sets of currents of different tre uencies havin its in wt circuit connected with one section and its output circuit connected with the other section, and ineans selectively responsive to the transmission of one of said sets to change the circuit connections to .modify the transmission of said set.

In witness whereof, I hereunto subscribe niy name this 6th day of l)e('en'1ber, A. I). 1.917.

- RAY S. 'WILBUR. 

